Process for dyeing furs, skins, hairs, feathers, or the like



2 g. of ammonia o Patented Sept- 20, 1927.

UNITED STATES PATENT OFFICE.

OSKAR KALTWASSEB, OF BERLIIT, HERMANN KIRCHHOFF, OF DESSAU, IN AN- HALT, GERMANY, ASSIGNORS TO- I. G. FARBENINDUSTRIE AKTIENGESELLSCHAFT, OF FRANKI'OBT-ON-THE-MAIN, GERMANY.

PROCESS FOBYDYETNG FURS, SKINS, HAIRS, FEATHERS, OR-THE LIKE.

Io Drawing. Application mecLAngust 9, 1926, Serial 'No. 128,332, and in Germany July 10, 1925.

B the present invention furs, skins, hairs, feathers, or the like are dyed with the aid of the diamino-2-hydroxyi1aphthalene obtainable by dinitrating naphthalene-L2- diazoxide, carefully treating the product with sodium sulphide and then reducing the nitrogroups, which product most probably is the 3.8-diamino-2-hydroxynaphthalene.

This compound is applied to the material to be dyed in aqueous solution in the presence of an oxidizing agent at a moderate temperature.

The following example illustrates the in- Vention without limiting it.

The well-washed skin is-handled at 30 C. for 2 hours in a bath containing per liter '2 g. of diamino-2hydroxynaphthalene hydrochlorate, 20 g. of hydrogen peroxide solution (of about 3 per cent strength) and per cent strength.

The skin is then rinsed, dried and finished as usual.

The dyeing on the unmordanted skin is brownish-gray. On a ferric mordant the dyeing is brownish-gray, on a chromic mordant it is dark-brown and on a cupric-mordant it is black-brown. I

That We claim is:

Process for dyeing furs,skins, hairs, and feathers, which comprises treating the material to be dyed, in the presence of an oxidizing agent, with a solution of the diamino-2- hydroxynaphthalene obtained by dinitrating naphthalene 1.2-diazoxide, carefully treat-j ing the product with sodium sulphide and thenreducing the nitrogroups.

In testimony whereof We afiix our signatures.

OSKAR KALTWASSER. .HERMANN KIRGHIHOFF. 

